Not 301st but 99BG. The short time used marking of 5BW often creates confusion among historians. In March '44 it was decided to use at the 5 BW the following symbols - Y in a square over the S/N at all groups and numbers 1-4 under the S/N. 1 stand for 2BG, 2 for 97BG, 3 for 99BG and 4 for 301BG. In April '44, when 463BG and 483BG joined the 5BW the new symbols were used for each group separately again.
Btw, this machine (42-31473 "My Baby") crashed not far away from where I live. Brother of the co-pilot (KIA) visited us and the crash site as well some years ago. Other pics of this machine are here, just scroll the page down B-17G, Nová Bošáca, SR | Letecká bitva Karpaty It also had 20 mm cannon in tail.
"... How many of those around were also collaborationists albeit in a less prominent way? Who know, but bet that more than a handful."
.. no question. It was France and women are women, but to answer your question figuratively, the Gendarme for starters.